Through the tinted windows of a green Cadillac sports utility vehicle, Conrad Black got his last glimpse of day-to-day freedom today as he sped across the Florida countryside to begin a new life as federal prisoner 18330-424.

Accompanied by his wife Barbara Amiel, the disgraced press baron swept past a phalanx of photographers as he emerged through the iron gates of his $28m (£14m) Palm Beach mansion shortly before 9am EST with an unidentified driver behind the wheel.

Three hours later, the car pulled into Coleman federal correctional complex near Orlando where the one-time Telegraph owner will serve his six and a half year sentence for fraud and obstruction of justice. The vehicle was inside for half an hour and emerged with Amiel as the only passenger.

Showing characteristic defiance to the end, Black quoted Winston Churchill in an interview with one of his former papers, Canada's National Post, declaring that his accusers "will have their fleeting moment of brutish triumph".

"It's no real triumph for them," he added. "It's a complete travesty of justice. It doesn't bother me because it won't last long."

The peer, who was stripped of the Conservative whip following his conviction last year, suggested he would use his time in jail to lose weight and that he would like "something bookish" as a prison job – perhaps, he suggested, teaching French to fellow inmates.

The one-time Telegraph owner remains adamant that he will prevail in an appeal likely to be heard this summer: "A moron who seriously looks at this case will see that it is a crock and I expect that it will ultimately be determined to be so."

Once among the world's most powerful media moguls, Montreal-born Black, 63, owned more than 200 papers at the height of his career including the Chicago Sun-Times and the Jerusalem Post as well as Britain's Telegraph titles. He had a fortune estimated at £136m.

He was convicted of embezzling more than $6m from his Hollinger empire through phoney "non-compete" agreements attached to the sale of newspaper titles – and of defying a subsequent court order by removing boxes of paperwork from his office.

In a comment article published today by several conservative newspapers, Black adopted a scattergun approach in assigning blame for his predicament.

Those accused by Black of overlooking his innocence include the US government, dissident shareholders, a special committee of Hollinger directors set up to investigate his actions, the media, the Ontario Securities Commission and his trial jury which, Black claims, reached a "compromise" on acquittals and convictions despite reasonable doubt.

Black's lawyer, Edward Greenspan, provided an unorthodox postscript to Black's highly complex three-month trial by admitting to a group of law students that he had regularly taken catnaps in court.

"I may have slept three of four minutes a day in court," Greenspan told an audience at the University of Western Ontario, complaining that he had little sleep at night because of the mountains of documents he was forced to study.

Greenspan took issue, however, with a juror who accused him of spending long periods with his eyes shut, saying the panellist "couldn't possibly have known because he was sleeping every day".